The Red Wings won their sixth straight, breaking open a 2-2 tie after two periods.
Holmstrom scored on a tip-in 4:22 into the final period while Eric Brewer was in the penalty box for hooking. Helm's insurance goal came with 6:46 remaining.
Detroit took a 2-0 lead after one period on goals from Pavel Datsyuk and Jonathan Ericsson. It was the first goal of the season for Ericsson and the 10th of his 186-game NHL career.